Ed Miliband is set to try to implement the first major change to Labour's founding principles for 17 years at this year's party conference.
In a move with strong echoes of Tony Blair's Clause Four campaign, when he scrapped the party's commitment to nationalising industry, Mr Miliband will insert a clause that brands Labour "a force for social justice".
Early reports of the document suggest there will also be a subtle but potentially important change in the party's organisational structure – Clause One.
Instead of aiming "to organise and maintain in parliament and in the country a political Labour party", the party will "bring together members and supporters who share its values to develop policies, make communities stronger through collective action and support, and promote the election of Labour representatives at all levels of the democratic process".
While the change sounds bureaucratic, it could herald wide-ranging alteration to the way the party operates. Mr Miliband hopes to introduce new categories of members, salvage Labour's economic prospects and encourage community organising.
The idea, originally proposed by Peter Hain, chair of the national policy forum, could see a registered supporters network bring in people who are non-partymembers who are willing to work on single-issue campaigns, such as local service cuts.
It could also ensure MPs demonstrate engagement with constituents via their candidate contract and trigger a wave of community campaign training.
Members of the public could also register as supporters, rather than members, and have a say in choosing party leaders. Such a move would replicate David Cameron's moves towards local primaries, by giving non-party supporters a say in which candidates are selected.
The proposals are particularly interesting, given that David Miliband had planned to reword Clause One if he became party leader.
They could anger union supporters, however, given they are already wary of the new Labour leader after he mooted plans to reduce their voting influence at party conferences.